get_depths: Match CTD points with closest hydro soundings

In fawda123/CTDplot: Plot CTD water quality data along an estuarine axis

Description

Match CTD points with closest hydro soundings

Usage

get_depths(
  ctd_pts,
  dep_pts,
  expand = 200,
  plot = FALSE,
  show_bath = TRUE,
  show_stat = TRUE,
  zoom = 12
)

Arguments

ctd_pts	data.frame of CTD station locations, see details
dep_pts	data.frame of depth sounding points, see details
expand	numeric for expanding sample size of CTD points
plot	logical to return plot of matched points
show_bath	logical to show bathymetric depth points on the plot
show_stat	logical to show stations on the plot
zoom	numeric for map zoom, passed to get_stamenmap

Details

CTD station locations are linearly expanded and then matched to the nearests points in the depth sounding layer. This is done to create a smoother depth gradient in the contour plot. The ctd_pts data.frame must have three columns for longitude (Long), latitude (Latitude), and station name (Station). The dep_pts data.frame should have three columns for longitude (Long), latitude (Latitude), and depth (Depth, non-negative). The plot argument can be used to verify the match of the interpolated points with the depth soundings.

All coordinates are assumed to be geographic decimal degrees using the WGS 1984 projection, negative longitude is west of the Prime Meridian.

Value

The expanded data.frame from ctd_pts including depth (Depth) and cumulative distance (Dist, in km) columns. If plot = TRUE, a ggmap plot is returned showing the matched points.

Examples

## Not run: 
dt <- as.Date('2014-04-21')
toplo <- ctd[ctd$Date %in% dt, ]
get_depths(toplo, PB_dep_pts)
get_depths(toplo, PB_dep_pts, plot = TRUE)

## End(Not run)

fawda123/CTDplot documentation built on Feb. 9, 2021, 2:02 p.m.